Ore-concentrating table.



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PATnNT Orrrcn.

ORE-CONCENTRATING TABLE.

SPECIFICATION forming part of Letters Patent No. 794,928, dated July 18, 1905.

Application iiled January 1'7, 1903. Serial No. 139.407.

To (L7/Z '1i/'hone may concern:

Beit known that I, I/VILLrs Cr. Donn, a citizen of the United States, residing in the city and county of San Francisco, State of California, have invented certain new and useful Improvements in Ore-Concentrating rIables, relating lmore particularly to that class of orc-concentrators known as transverselyinclined reciprocating riflied tables/ and pertains specially-to the method of arranging the riffles upon the working face of such tables, of which the following is a specification.

The usual type of transversely -inclined concentrating-table of the class referred to when in operation has a peculiar reciprocating motion imparted to it, which motion has a tendency to carry material fed thereon longitudinally toward the foot or tail of the table. The working face of the table proper has arranged upon its surface a series of longitudinal deflecting slats or riflies extending from the head of the table toward the foot or tail thereof, said riifles terminating in such a manner as to leave a plain, smooth, or unriflied portion of the table between the terminals of the rifl'les and the foot or tail of the table, onto which the mineral and gangue which may have been collected by the riii'les is discharged, and final separation of the mineral from the gangue is effected by subjecting it to a transverse How of clear water while it is being carried forward onto the plain, smooth, or unrifl'led portion. The pulp, which consists of a mixture of water carrying a small quantity of finely-crushed grains of valuable mineral intermingled with la large quantity of finely-crushed quartz, when fed upon the upper edge of the table flows transversely downward over and across the riflied portion of the table at approximately a right angle to the line of motion or to the longitudinal direction of the riffles. The mineral in the pulp having a specific gravity much greater than that of the gangue or quartz is arrested in its transverse downward course, settles or becomes entangled among the riffles, and due to the peculiar longitudinal reciprocating motion given the table is carried longitudinally along the riifles and is discharged upon the plain, smooth, or unriffled portion of the table above referred to. This transverse flow of the gangue over the riffles in a succession of miniature Niagaras across the path of the valuable mineral which is being conveyed toward the foot or tail of the table along the riffles keeps the mineral while being collected in a constant state of agitation and causes the finer particles of mineral to be carried with the worthless gangue and is discharged over the lower edge of the table, where these particles are finally lost. Said distributer is arranged a slight distance above the surface of the concentratingtable and so located that the pulp discharged therefrom will be received onto the tables surface immediately in advance of the uppermost or shortest riflie of the series of collecting-riffles.

The object of my present invention is to decrease this loss by unloading the riflles of a portion of the gangue, which I accomplish by a special arrangement of the riflles on the working face of the table, leaving a plain, smooth, or unriffled portion between the head of the table and the receiving ends of the rifl'les, upon which surface a partial separation of the gangue from the mineral is effected prior to entering the riiiles for further treatment, all of which is set forth and illustrated in the accompanying drawings, which form a part of this specification, wherein- Figure l is a plan view of a transversely- ,t

inclined reciprocating concentrating-table fitted with my improved method of riflfling, and Fig. 2 is an end view of same in crosssection.

The letter A represents the table proper of a concentrating-machine of the class described, the face of which is usually covered with sheet-rubber or linoleum, or any suitable material may be used that will produce a smooth and even surface to the working face of the table. Upon this smooth working face of the table a series of deflectingslats or mineral-collecting rifI'les B, usually consisting of tapering strips of wood, are secured. These rifl'les are of varying length, the shortest usually being the uppermost, and they are so arranged that the receiving IOO end and the terminal end of each successive riflie from the uppermost downward advance beyond the receiving end and the terminal end of the riffle above, thus leaving a smooth or unriifled portion of the table C between the receiving ends of the riliies and the head D of the table and a smooth or iiiiriffled portion of the table E between the discharge ends of the riffles and the foot or tail of the table F.

A feed-box or distributer G is suitably mounted or secured to the table and is provided with a perforated bottom, which sifts or distributes the material to be concentrated upon the table. A water-distributer H is suitably suspended at and above the upper edge of the table, from which, through suitable openings, clear water as required is delivered onto the table.

J is any suitable driving mechanism that will impart to the table a reciprocating motion that will impel the material delivered to the riflles longitudinally toward the foot or tail of the table.

K is a sluice or launder by means of which the material to be concentrated is conveyed from any suitable crushing device into the feed-box or distributer G.

The operation of the concentrator is as follows: The table A is given a slight transverse inclination suflicient to permit the pulp to flow downward over the smooth or unriflled portion C between the receiving ends of the riffles and the head D of the table. Power is then applied by any suitable means to the driving mechanism J, which imp arts a reciprocating motion to the table. Pulp, consisting of water carrying finely-crushed quartz containing a small quantity of finely-crushed mineral is now introduced by means of the sluice K into the feed-box G, from which it is sifted or distributed onto the smooth or unriffled portion C of the table A, adjacent to the receiving ends of the rifiies. As soon as this pulp is deposited upon the smooth surface of the table the quartz or gangue flows downward and is entangled among the receiving ends of the lower ri'lfles and after depositing any particles of mineral that may have been carried with it is permitted to run to Waste. The mineral contained in the pulp, due to its specilic gravity being greater than the quartz or gangue associated with it, settles and clings to the table, moving slowly downward in a diagonal. direction, due to the motion given the table, and becomes entangled with the advancing receiving ends of the riifles, enters them, and is carried longitudinally along the tapering rifi'les, and is discharged upon the smooth or unri'l'l'led portion of the table E, where the linal separation of the gangue from the mineral is effected by subjecting it to the action of a transverse flow of clear water delivered upon the table from the water-distributer H, the mineral being carried over the foot or tail of the table and deposited in a box or receptacle provided for the purpose. The middlings produced, being a mixture of mineral containinga small quantity of quartz, are conducted into a special receptacle, from which they are returned to the table by any suitable device for reworking. l

By the method of riffling herein described l am enabled to effect a partial separation of the mineral from the gangue before delivering it to the rifl'les, thus relieving them from a part of the load of pulp that has heretofore been necessary to pass over them and by avoiding excessive disturbance to the mineral while traveling along the riffles reduce the loss of line particles to a minimum.

Having thus described the invention, what is claimed as new, and desired to be protected by Letters Patent, is-

l. A transversely-inclined ore-concentrating table provided on its working face with a series of longitudinally-extending collectingri'll'les, which riliies gradually increase in length from the uppermost riffle to the lowermost one of the series, the receiving and terminal ends of each riflle extending beyond the said ends of the preceding riffle, there being an unriffled or plain surface to the table intermediate the terminals of the riflies and its head and tail respectively, and feeding means so arranged at the upper edge of the table as to cause a portion of the pulp delivered onto the table to overlap the uppermost riffle toward the head, so as to feed directly to the projecting ends of part of the subsequent ri'l'l'les.

2. An ore-concentrating table provided on its working face with a series of longitudinally-extending collecting-riffles, which rifiies gradually increase in length from the uppermost riffle to the lowermost one of the series, the receiving end of each riiiie extending beyond the receiving end of the preceding rifile, there being an unriffled surface to the table intermediate its head end and the receiving end of the riflles, and feeding means so arranged at the upper edge of the table as to cause a portion of the pulp delivered onto the table to overlap the uppermost riflie toward the head, so as to feed directly to the projecting ends of part of the subsequent riffles.

In witness whereof l have hereunto set my hand.

WILLIS G. DODD.

Witnesses:

WALTER F. VANE, D. B. RIorIARDs.

IOO 

